1. Field of the Invention
The present invention generally relates to munitions and, more particularly, is concerned with a temperature compensating variable stroke projectile positioning system for adjusting primary propellant chamber volume for separate loaded ammunition.
2. Description of the Prior Art
Projectile munitions have varied performance dependent on environmental temperatures. Propellants of the munitions typically provide high performance under high ambient temperatures. However, under cold conditions such munitions exhibit low performance due to the slower burn rate or degradation of propellants.
To increase performance of cold munitions, the temperature of propellants may be increased. However, such heated munitions may be dangerous if designed for maximum performance under colder environmental conditions. So for reasons of safety of firing crews and of avoiding excessive stress on firing mechanisms, most munitions are designed to reach maximum allowable pressure only at high ambient temperatures. Such a design results in low performance munitions at medium or low temperature climatic conditions.
Two approaches to temperature compensating control of projectile munitions propellants for improving munitions performance at all environmental temperatures, i.e., temperature independent performance, are disclosed in the patent applications cross-referenced above (but are not considered to be prior art to the present invention). In the first cross-referenced application, temperature compensation is achieved by changing the volume of the container holding the primary propellant by moving the projectile using a temperature-sensitive secondary charge-driven piston.
Although both of these approaches constitute steps in right direction, other approaches still need to be explored in searching for ways to ensure optimal performance of projectile munitions at all environmental temperatures.